Effect of Photochemical Aging on Residential Wood Combustion Aerosol Toxicity in Airway Epithelial Models at the Air–Liquid Interface
SVENJA OFFER, Hendryk Czech, Sebastiano Di Bucchianico, Mika Ihalainen, Pasi Yli-Pirilä, Olli Sippula, Yinon Rudich, Ralf Zimmermann,
Helmholtz Zentrum München Abstract Number: 313
Working Group: Health-Related Aerosols
AbstractResidential wood combustion (RWC) substantially contributes to the burden of disease attributable to air pollutants by emissions of carbonyl compounds and fine particulate matter (PM
2.5), which have been associated with adverse human health effects. However, there is only limited knowledge on how atmospheric aging affects the toxicological impacts of emissions.
To study those effects, we burned beech logwood in a chimney stove and aged the emissions in a high-volume oxidation flow reactor “PEAR” for equivalent photochemical ages accounted as 1.4 and 3.3 days by using d9-butanol as photochemical clock. To discriminate toxicological effects, we exposed two cell model systems consisting of either epithelial (A549) or bronchial (BEAS-2B) cell lines at the air-liquid interface for 4 h to the generated fresh, 1.4 or 3.3 days aged RWC aerosols.
In general, we observed considerable toxicity-related outcomes in cells treated with the emissions of RWC. Greater adverse effects were measured for aged compared to fresh aerosols, with some indications of enhanced adverse effects for the longer aging condition. At the functional level, we found that aging of RWC augmented the secretion of malondialdehyde and induced changes in the glutathione redox homeostasis, pointing towards the occurrence of intracellular oxidative stress. The accumulation of the cytotoxic marker lactate dehydrogenase (LDH) in the cell culture media and the reduced metabolic activity of both cell models after the exposure to especially aged RWC emissions, further confirmed the enhanced cellular toxicity induced by photochemical aging. Additionally, longer aging of RWC emissions slightly caused greater LDH release and metabolic activity impairment compared to shorter aging condition.
Altogether, our study highlights the importance of photochemical aging on enhancing toxicity-related outcomes by detecting greater adverse effects after the exposure to aged RWC emissions than fresh emissions in both cell models, with stronger effects of the longer aged RWC emission.